Heat treatment



April 21, 1942 .I

H. E. SOMES HEAT TREATMENT Filed June 8, 1939 -2 Sheets-Sheet l 1.... ,fw P

ATTORNEY.

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pril 21, 1942. H. E. soMEs 2,280,102

' HEAT TREATMENT l FiledJune 8, 1939 zsneets-sneetz Hwurdomes w` BHW-2m? Puentes Apr. 21,4942

UNITED vs'nrrss PATENT ol-"rlciis 'y l :ssamm .l

mr'mns'rm'r animan son, am remerci, man., .emmemttrmmmm- Application June 8, 1939, Serial No. 277,995

zlclaims. (Chris- 13) j This invention relates heat treating `by electro-magnetic induction andI more particularly heat treatment of the internalsurfaee of relatively thin metallic sleeves.

In heat treating the internal surface of sleevelike bodies by electro-magnetic induction the inside laycrs are broughtto a relatively `high temperature quickly and thereafter quenched to 4invention will appear more fully hereinafter from the following detailed description when taken in connection with the accompanying drawings. It is expressly understood, however, that the drawl ings are employed for purposes-of illustration only and are not designed as a definition of the limits ofthe invention, reference being had for this purpose to the lappended claims.

In the drawings wherein similar reference characters refer to similar parts throughout the several views:

Figure 1 is a longitudinal section taken through a work sleeve and supporting sleeve and an electro-magnetic inductionheating unit.

Figure 2 is a section taken on the line 2-2 oi Figure 1.

Figure 3 is a longitudinalsection through a modmed form or the invention.

rapid heating-because of the .ability to induce exceedingly great currents in the sleeve being treated. f j

The present invention relates to a supporting sleeve adapted for use'in connection with sleeves which are to be heat treated, the-supporting sleeve .being formed of magnetic material and adapted to not only lower the reluctance of the magnetic path but in addition is adapted to render physical support to the sleeve itself to the end that its shape may be positively maintained, regardless of the'degree or depth of heat treatment in the internal surface or the thinnessof Ani'iliject'of the invention,` therefore,is to progide a supporting sleeve adaptedv to cooperate with-awork-piece in the formof a -sleeve to be heat .treated by electro-magneticinduction Another object of the invention is to provide a readily removable from to be matted.`

' further object of the invention is to provide "an auxiliary sleeve of magnetic .flux conducting material which may operate in condunction with 'a work sleeve to be heat-treated and assist in concentrating the heat treating currents induced afford a maximum-rate of heating as wellas ren` der support to the sleeve during such treatment'.

" Asleeve as hereinabove suggested which will be the work sleeve -which is s ducmg con n'wmcn is insuiated from the core Figure 4 is a section taken o n the line 4-4- of Figure 3.v

Figure 5is a longitudinal section through another modification of theJnvention and,

Figure 6 isa section taken on the line t-G of Figure. l r

Referring to Figure l thereis case is provided with an annular internally shou1. dered member i4 bolted to the work support shown a work e supporting member Il and a heat treating hed'f I2 which are relatively movable with respect to eachother. The work supporting member in this Il of magnetic material such as Armco iron which sleevehas an internal bore adapted to fit and support a work cylinder sleeve 20 for heat treatment. 'I'he jacket I8 with the work cylinder sleeve 2l therein is adapted to be removed from the annular shouldered member i4 after each operation `and a new sleeve 2U inserted and the 'jacket thereafter replaced in the/lapos/ition shown.

'I'he heat treating head is of t e electro-magl netic induction type andcomprises a central supporting arbor 22 'and carries thereon lan annular `magnetic core 24 f Ispoor` shape having end flanges 2l andcomposed of radially tapered laminations 26. -Around the magnetic core is an inand which'. is composed of hollow watercooledconductors, in the present instjance two condutors in parallel be shown., ./f

The magnetic core 24. is held on the arbonby clamping the same between the nut 30 and the shoulder f orned by the'disc 32. 'I'he nut 3l may also act as a pilot to center the head with respect The labove and other novel features of the `to the supporting member I0. The coil connec an insulating block 40 and connecting to an ex' ternal insulated shell 42 forming a part of the arbo'r 22. The particular details of the heating tool do not form a part of the present invention and the same may be constructed as hereinbefore described or in any suitable manner such as described in my copending application Serial No. 96,346. filed August 17, 1936.

The work cylinder sleeve 2@ which is adapted to be heat treated by the present apparatus is illustrated as of shorter length than the heating coil threaded therethrough and consequently in order to assist in the concentrating of ux, nifagnetic end pieces are required to complete a magnetic path of high permeability to the flanged ends 2 5 of the magnetic core 2d. For this purpose a plurality of radially arranged tapered laminations 4S. are secured in place'beytweena shoulderedsleeve 46 and disc 33 and bridge the gap between Athe upper flanged end of the magnetic core 2l and the upper edge of the cylinder sleeve and its jacket it. In a moved from the sleeves after treatment and cooling.v In many cylinder sleeves a shoulder such as is illustrated may be provided and this shoulder may conform to a complementary recess formed in the jacket so that the parts when assembled will remain assembled during the insertion into and out of the machine.

in Figure 3 there is shown a modified form of the invention. The jacket surrounding the sleeve to be heat treated in this instance is composed of an external sleeve '60 having arranged along its innersurface a pluralitypf radially positioned and tapered laminations 82. The laminations are held in position by the complementary notches 66 on the internal'surface of the external sleeve 6G similar fashion the lower end ci the cylinder inder sleeve byitself would be too thin. Also they are of the same length so that their ends may be substantially flush. In practice, a sleeve is arranged in a jacket and/the jacket seated upon the internal annular shoulderl I6 of the annular member Il. The heat treating tool is then inserted within the cylinder sleeve and brought to the position in Figure 1. The heating coil is then energized from' a suitable source of high frequency current such as 2,500 cycles and the internal surface of the cylinder sleeve is immediately brought to a plastic heat preferably in less than two seconds. Thereafter the heat treating wol is removed from the sleeve and the jacket and sleeve removed from the work support member or if desired, quenched in position and thereafter removed. ,While the cylinder sleeve and its jacket will have a close il't when initially assembled for heat treatment, subsequentto the heat. treatment no dilculty will be found to einst in removing the sleeve from the jacket for the reason that the sleeve will be found to have shrunk slightly away fromthe jacket as a`result of the heat treatment. The jacket in addition to providing a magnetic path and thereby assisting in the concentration of the flux also maintains the cylinder sleeve while undergoing treatment in its proper shape regardless of the depth of heat treatment. It vwill be understood that in such heat treatment of-thin .walledmembers as the-cylinder sleeves herein f described the sudden rendering plastic of as -much as half 'the thickness of the member would normally weaken the member and possibly cause i thesame to lose. its shape were it not for the and the outer edges of the laminations respectively and also by a complementary notch and annular ridge 66 in the upper end of the laminations and a disc member 68 respectively, the lat# ter being fastened to the external sleeve 60 by screws l0. The inner edges 'l2 of the laminations o2 are cut to' nt a work, cylinder sleeve such as l in much the same manner as the jacket i8 in sleeve 20 in the modification of Figure 1. -In the present modification, however, the laminations 62 are extended at the .upper end as at 16 so as to provide the necessary annular bridge to complete the magnetic circuit to the flanged end 25' of the inductor magnetic core 18. At the lower end, the magnetic circuit is completed by a plurality of radially arranged tapered laminations which are clamped between the work support member l2 and and an annular shouldered ring I4 bolted thereto. The external sleeve 60 of the supporting jacket` is provided at its lower end with a flange Il cooperating with the shouldered ring ofannular member 84 so as to correctly position the supporting `jacket and the cylinder sleeve to be treated in s correct position with respect to the axis of the heat treating inductor. j A

In Figure 5 a further modification is shown wherein the jacket is composed of two parts separating. substantially in the center. As shown the jacket is composed of a pair of top and bottom shell members Il and l2 having tapered lengaging surfaces Il and Il. Each shell member is in turn provided with a liner of magnetic lammay be forced into their enclosing shell Il. The

lower han or the sneu4 s: a also provided with laminations Nl similar to those in the upper shell and the laminations are held in place by a shoulder m and the end plm m, the sneu and end plate being secured together -by suitable fastening meansv I Il. 'fr

It will be seen in the modification in Figure 5 that the upper half of the jacket is carried by the heat treatment tool or head and whenA the head 'is raised the upper half of the shell is vseparated from the lower half thereby leaving the cylinder sleeve IIB exposed for removal or the lower shell exposed for inserting a new sleeve. 1

Inail of the modications, since the cylinder sleeve is heated to a temperature suitable for the radial outer side to support the saine and ex' comprising a plurality of radially disposed lamiheat`treatment, the heat treating head is im- -and by reason of the employing of an inducing coil longer than the cylinder to be treated together with the bridgevportions at either end of the sleeve-to be heat treated, the uniformity of tending around the ends of vsaid -sleeveandvradially inward substantially' to said cylindrical surface, said core and said circuit being substantially circularly continuous. Y

4. A jacket for encasing a thin walled cylindrical sleeve for electro-magnetic induction heat treatment of the internal layers of the sleeve,

nations of magnetic flux conducting material, arranged to'form an enclosing cylinder, a supporting sleeve for said'laminations, and the internal edges of said laminated material forming a wall adapted to closely embrace a sleeveto which heat treatment is to be effected.

5. A workholder c omprising in combination ajacket and 4radially arranged laminations of magnetic material within th'e jack forming a I -sleeve of magnetic material, means on the jacket the induced currents is more certain assured..`

' In the modifications of Figures 1 and 5 the sleeve lis shown as directly Asupported throughout its external surface by the cylinder jacket.` This may also be true of the sleeve in Figure 3 should it seem desirable to have such support present. For various outer surface contouys of cylinder sleeves different adapters maybe constructed s0 that there will be provided the necessary flux path as well as the necessary support in any particular case. j Although several modifications of the invention' have been disclosed, it is, of course, understood that the invention is ,not limited thereto f but that the same may be embodied. in various mechanical forms and arrangements.

As many changes in construction and design may be vmade without departing from the spirit of the invention as will be apparent to those skilled in the art, reference will be had to the appended claims for adefinition of thelimits of the invention.

VWhat is claimed is: 1. The method of heat treating by electromagnetic induction the internal surface of a thinv hollow vcylindrical member which comprises closely embracing said member in a tubularjacket of magnetic material, including said member and jacket `as va part of a magnetic'circuit, inducing a heat treating current in said member,

' and removing the jacket from the member thereafter. i"

2. The method of electro-magnetic induction heat treating the internal -surface and adjacent layers of a thin metallic sleeve which com'- prises enclosing-saidsleeve in an external complementa] flux carrying and supporting jacket,

Vinducing heat treating currents in said sleeve while passing flux thru said jacket, andsubsequently removing the sleeve from the jacket.

andassociated therewith for securing said laminations in place, said -laminations having their inner edges formed with a recess suitable for snugly engaging a thin walled cylindrical memben 6. Apparatus for heat-treating an elongatedA object comprising an electro-magnetic induction v. heating element arranged to generate a current inducing field extending longitudinally lof the' object beyond the ends thereof and means c omposed of magnetic material arranged adjacent a lateral face of the object to for'm end extensions of said object extending into the extended portions of said field.

7. Apparatus for heat-treating an elongated object by electro-magnetic induction comprising low reluctance means arranged to form end extensions of said object connected by magnetic material, an electro-m netic induction heating element of a length greater 4than that ofthe object and means for effecting relative movement between the object and the heating element/to bring the object and ythe end extensions into the magnetic ld of the heating element.

8'. Apparatus for heat-treating 'the inner surface portionof a hollow cylindrical object comprising annular end extension pieces of laminated magnetic material arranged each to form an 4end extension of one end of the object with its laminae extending in radial planes parallel to the axis of 'the object, an electro-magnetic inducing element having an internal magnetic core element arranged to fit within the hollow of the object with the ends of the core element extending into close proximity to the said end extension pieces, means for 'effecting relative motionbetween said inducing element and said object and end piecesto bring them into'inductiverelation, and a mechanical connection between said end extension pieces located radially outside said object and constituting a centering guide for said object.

9. A flux carrying and supporting jacket for supporting thin sleeves for electro-magnetic in` duction internal heat treatment, comprising a shell, composed of two concentric parts arranged end. to end and having conical mating faces,

3. Apparatus for heat treating a thin cylin- 'i drical sleeve internally, comprising an inducing coil lying withina cylindrical surface substanj- 'tially that'of-'the internal bore of said sleeve, a

magnetic core' for said coil extending thru the coil and outwardly to said surface at either end thereof, .a magnetic circuit for said sleeve external thereto closely embracing said sleeve on radially arranged thin sector sectioned somewhat similar laminations arranged internally of each of the two parts and adapted to provide a continuous magnetic path from top to bottom, and a smooth internal sleeve supporting surface within said laminations.

10. In the methodofheat-treating a circumferentially continuous metal sleeve of substantially uniform thickness which is so thin as to be in danger of becoming deformed under heat when somewhat plastic throughout enough of its radial depth for any remaining part of its radial depth to be incapable of supporting the heated portion against such deformation during heat treatment, the improvement which includes electromagnetically inducing heating currents intoone face of the sleeve and simultaneously supporting said sleeve from its surface opposite said first-mentioned faceI by :a wall to oppose any tendency for the sleeve to be deformed during heating, the supporting of said sleeve being from a wall surface iitting the sleeve throughout at least a substantial part ofits axialextent.`

11. In an apparatus for heat-treating a circumferentially continuous metal sleeve of substantially uniform thickness by electromagnetic induction when it isso thin as to be in danger of not holding its shape during heat treatment, having an inducing conductor adjacent the sleeve, the improvement which-includes a' supporting wall of magnetic material contiguous said sleeve on its face opposite to said conductor and having a fit with said sleeve capable` of gripping and supporting the same`against deformation during heating.

12. In an apparatus for heating a circumferentially continuous metal sleeve of substantially uniform thickness by electromagnetic induction when said sleeve is so thin as to be in danger of uniform thickness by electromagnetic induction when said sleeve is so thin as to be in danger of not holding its shape during treatment, an inaxially for removal of the sleeve from said recess. i 16. The method of heat-treating a metal sleeve -which is to be heated by electromagnetic induction for substantially its fullradial depth4 which comprises electromagnetically inducing a heating current into the sleeve in a manner to heat it substantially throughout enough of its radial depth to a plastic condition so that no radially outer unheated layers of the sleeve are strong enough to oppose its expansion, simultaneously circumferentially and uniformly compressing said sleeve to render the material thereof more compact, and subsequently cooling the sleeve to reduce its outside diameter compared to what it was before heating.

17. In an apparatus, for heating a sleeve by electromagnetic induction when said sleeve is so thin as to be in danger of not holding its shape during heat treatment, having an inducing coll, the improvement which comprises an annulus of magnetic material onto which said sleeve may be slid with a fit such that said sleeve when expanded by heat to a somewhat plastic condition will be supported by said annulus against deformation due to the heattreatment, and a shoulder contiguous said annulus against which said ducting coil, a rigid supporting annulus of mag.-

'netic material on the face of the sleeve oppotherewith, whereby any radially outward thrusts .en said laminations edgewise due to internal stresses from heating said sleeve are transmitted to said ring.

14. In an apparatus for heating a sleeve when Y the sleeve is to be heated by electromagnetic induction substantially through its radial depth,

having an inducing coil, and a rigid supporting i annulus of magnetic material adjacent said coil,

the improvement in said annulus which includes a circumferential recess of a size to receive said sleeve adjacent said coil and longitudinally lntermediate the ends of said annulus, saldannulus being transaxially split intermediateits ends for removal of said sleeve, the cooperating sleeve is adapted to abut.

18. In an apparatus for heating .a sleeve by electromagnetic induction having an inducing coil, and an annulus of magnetic material lncluding a laminated ring radially contiguous said sleeve, the improvement which comprises a member at one end of saidl annulus for axially aligning one end of the coil and the adjacent end of the annulus, said member and annulus being provided with interengaging aligning portions.

19. In an apparatus for heattreating a-sleeve by electromagnetic induction when the sleeve to be h eated is so thin that it is in danger of deformation by heat treatment, having an inducing coil, and a rigid supporting annulusof magnetic material adjacent said coil, the improvement in said annulus which' includes `a circumferentiall recess of an axial length and radial depth to receive said sleeve contiguous said annulus and adjacent said coil, said annulus being split inter-l mediate the ends of saidrecess and sleeve for removal of said sleeve, at least a portion of said splitv being conical to provide centering surfaces for telescopic engagement of the sleeve portions,

and each of the split portions of said annulus including a rigid ring contiguous radial laminations therein which are contiguous said sleeve and extend around an end portion of the sleeve split portions of said annulus being provided'with interaligning means.

l5. Invan apparatus for heat-treating a eir-Y cumferentially continuous metal -sleeve of substantially uniform thickness by electromagnetic 2,280,102 5 throughout. at iwtaumtmuauy the :un ,length A of the work being heated, and means associated d with the backing for positioning the work relative thereto, whereby a flux path in addition to the work is provided when the depth of the work is relatively shallow. j

2l. An apparatus for the inductive heating of,

y work in the form of a ring, which includes an inducing coll adapte-d to lie adjacent one face ol' the work, and magnetic material contiguous the opposite face ot the work from said coil and extending axially of, and adjacent and beyondy each end of the work and to a position substantially uah with the work i'ace adjacent which the 'c'oil lies.

HOWARD E. SOMES. 

